My Ruby Profiler - wraps code to be profiled and prints result in a nice way (uses ruby-prof)

dev_profiler.rb

require 'ruby-prof'
#
# This will use ruby-prof and print in a nice way.
#
# Input params:
#   file_name = File name of output
#   printer   = graph || flat || stack
#
# Output format:
# E.g.:
#   tmp/profilers/something-2418870541/graph.html
#                                      flat.html
#                                      stack.html

module DevProfiler
  def self.profile(file_name, printer = 'stack', &block)
    dir = File.join(Rails.root, 'tmp', 'profilers' )

    # Create dir automatically
    FileUtils.mkdir_p dir unless File.exist? dir

    # Do the profiling
    RubyProf.start
    block_response = block.call
    result = RubyProf.stop

    subdir = File.join(dir, "#{file_name}-#{Time.now.to_i}")
    FileUtils.mkdir_p subdir unless File.exist? subdir

    if printer == 'graph'
      File.open(File.join(subdir, 'graph.html'), 'w') do |file|
        RubyProf::GraphHtmlPrinter.new(result).print(file)
      end
    elsif printer == 'flat'
      File.open(File.join(subdir, 'flat.txt'), 'w') do |file|
        RubyProf::FlatPrinterWithLineNumbers.new(result).print(file)
      end
    else
      File.open(File.join(subdir, 'stack.html'), 'w') do |file|
        RubyProf::CallStackPrinter.new(result).print(file)
      end
    end

    # Make sure to return the block response still
    block_response
  end
end